Spliced cord



R mm W WA 5 mm I I -"I" I I D .1 a T3 E 3 E I N W I Q t w x L f c m BYfio'gzmt Mam AT TORN EY June 3, 1969 w. o. ALEXANDER SPLICED CORDOriginal Filed Sept. 10, 1965 June 3, 1969 w.'|: ALEXANDER 3,447,309

SPLICED CORD Original Filed Sept. 10, 1965 Sheet 2 of 2 FIXED UNTWISTINGPOINT POINT TWIST LOST TWIST T STORED FIG.3.

SITE OF UNION SITE OF UNION SITE OF' UNION INVENTOR WAYNE D. ALEXANDERRM a- Han/mm ATTORN E-Y United States Patent US. Cl. 57-142 2 ClaimsABSTRACT OF THE DISCLOSURE A pair of multi-ply twisted cords areuntwisted and spliced to minimize the bulk thereof by joining theseparated strands at staggered sites along the cord. The cord is thentwisted to restore the original twist. The spliced cords areparticularly characterized by the yarn pairs being overlapped from A to3 inches to improve the uniformity, strength and flexibility of theregion of splice.

This is a division of application Ser. No. 307,891 filed Sept. 10, 1963,now US. Patent No. 3,315,458.

This invention relates to the joining of multi-ply twisted cord or likestructures; i.e. cords or the like composed of two or more yarns orstrands, and more particularly to a splicing method and apparatus, andto spliced multiply twisted cords of improved uniformity.

In textile and industrial applications of fiber structures consisting ofat least two distinct individual strands or yarns twisted together, andespecially plied or cabled structures, e.g. cords, it is generally foundundesirable to have knots or other protuberances such as usually resultfrom splicing lengths of a cord or like structure. Not only do suchprotuberances cause snagging of the cord through handling means such asguides and needles, but such protuberances contribute to defects inappearance and in utility. Splices formed by use of adhesives may bemade relatively non-bulky, but are generally weak unless the individualyarn ends to be joined are extensively overlapped, in which case thethickness of a twisted cord throughout the region of splices isapproximately doubled.

In cords intended for industrial application such as reinforcement oftires or conveyor belts, and other applications wherein cord strengthand uniformity are critical, it is essential that variations of cordthickness or denier, strength, and twist be maintained small throughout.In a rubber tire re-inforced with spliced cord of two ply constructionor greater, for example, any sizable variation in the cord twist in theregion of splice will produce resultant torque upon the reinforcedstructure and constitute a source of potential tire failure.

It is an object of this invention to provide improved spliced multi-plytwisted cords and like twisted or cabled structures. It i another objectof this invention to provide a method for uniting multi-ply twistedcords without appreciably affecting the denier, strength, twist, or bulkof the cord in the region of the splice. It is a still further object ofthis invention to provide novel apparatus for the splicing of multi-plytwisted cords in such fashion as to regain the original cord twistwithin the region of splice after splicing. Other objects and advantageswill become apparent hereinafter. Wherever cords are referred to hereinit is to be understood that like twist structures, and also cabledstructures, are broadly included in the scope of this term.

The splicing method of this invention consists essentially of thefollowing steps: gripping at two spaced locations each of two like cordswhich are to be spliced, viz. at a terminal gripping location toward theend of the cord and at an interior gripping location toward the mainlength of the cord, thus defining a gripped segment of each cord, alongwhich uncontrolled torsional and longitudinal cord movement isprevented, the two gripper segments being made approximately equal inlength; aligning said gripped segments with the terminal grippinglocation of each cord aligned with the interior gripping location of theother cord; removing the twist from the gripped segement of one cord byrotating said first gripped segment together with the terminal grippinglocation; removing the twist from the gripped segment of the second cordby rotating said second gripped segment together with the interiorgripping location thereof thus building up and storing in the mainlength of said second cord the same amount of twist as it removed fromthe gripped segment thereof; separating the individual yarns or strandscomposing the gripped segments; uniting each yarn of said first segmentto a yarn of said second segment at nonoverlapping sites to form aregion of splices; said sites where union is made being so chosen thatthe yarn length for each united pair of yarns, from one interiorgripping location to the site of union and on to the other interiorgripping location is equal for all the united pairs of yarns; freeingthe yarn ends for movement about the cords; and then giving the grippinglocation of the second cord the same number of turns of rotation aspreviously but in the opposite sense, thereby restoring the originalamount of twist in the region of splice and in the main length of thesecond cord. Preferably this last step is accomplished by positivelyrotating the gripping location of the second cord to remove the storedtwist from the main length and impart it to the region of splicesbetween the two interior gripping locations of the two cords which havebeen spliced.

Uniting of the individual yarns may be effected by methods such asapplication of adhesives, knotting, sewing, fusing, or analogous means;and the uniting may be effected by hand or mechanically. Methodsinvolving adhesives, sewing, or fusing, require some overlapping of thepaired yarns. Preferably the yarns will overlap by about inch to 3inches. The sites at which the various pairs of yarn are united Will bestaggered along the region of splice to avoid overlapping of any twosuch sites. It is important that these various sites of union be sochosen that the united yarn from one interior gripping location to thesite of union and on to the other interior gripping location will beequal for all yarn pairs. Otherwise, the spliced cord would containslack or looped yarn in the region of splice. Normally this requiredequal length will be the length of the two equally long gripped segmentsof the cords being joined, less the length of overlap between the pairedyarns.

The ends of the yarns are conveniently freed for ID- tation after theuniting of the yarn pairs, by cutting, melting, burning, or likesevering operation. This severance will usually be made as close aspossible to the site of union of the yarns so as to avoid as far aspossible protruding out. The severing operation can also be effectedbefore the uniting operation by use of auxiliary clamping means whichhold the paired yarns in position to be united. Severing prior touniting allows overlapping and uniting the full length of the severedends, thereby entirely avoiding protruding ends in the spliced cord.

The splicing method of this invention is capable of rapid manual orautomatic execution and is eminently suited for use in commercialoperations of cord production or utilization. The gripping means forpreventing uncontrolled cord movement suitably takes the form of springor screw operated clamps, or hooks or posts or compact coil springsabout which the cords are looped or tied or fastened. The terminalgripping means for one cord and the internal gripping means for thesecond cord are mounted on, or are part of suitable rotatable supports,whereby the corresponding gripping locations of these cords can berotated. The length of the gripped segments is for example from about 4to 20 inches depending on cord diameter and twist.

These gripped segments can be aligned close together throughout theirlength or can intersect preferably at an acute angle. The segmentsshould lie fairly close so that they are separated by not more thanabout 5 inches throuout the region of splice.

The order in which the two segments are untwisted is immaterial, itbeing preferred however, for speed of operation, that both segments beuntwisted simultaneously. Novel apparatus is provided by this inventionto achieve such improvement. Once the cords are untwisted, theindividual yarns thereof may be separated by hand or mechanically.

The spliced cords of this invention are characterized by havingthroughout, including the region of the splice, the same twist; and byhaving in the region of splice no greater denier than about d(l-|l/n)where d is the denier of the main length of the cord and n is the numberof individual yarns or strands composing the cord. Thus, a two ply cordwill have denier in the region of the splice of not more than about 50%greater than that of the main cord; a three ply cord will have denier ofnot more than about 35% greater than the main cord. The strength of thesplice in our cords will be at least about 75% of the strength of theunspliced cord, as determined by tensile strength tests of spliced andunspliced cord portions. The flexibility r suppleness of the cord isessentially unaltered in the region of the splice contrary to previoussplicing techniques using adhesives, which result in a stiffening of thestrand throughout the entire region of the splice. Spliced cords of thisinvention perform satisfactorily in conventional cord handling orprocessing operations, and lead to the production of improved endproducts fabricated therefrom.

The invention will be more fully explained in conjunction with thedrawings wherein:

FIGURE 1 is an elevation illustrating a preferred embodiment of theapparatus of this invention.

FIGURE 2 is an elevation illustrating another embodiment of theapparatus of this invention.

FIGURE 3 is a schematic diagram illustrating the process features ofthis invention.

FIGURE 4 is an illustration of the spliced cord of this invention, shownas being expanded for greater clarity.

Referring now to the drawings, the apparatus of FIG- URE 1 comprises abase 1 which rigidly supports arms 2 and 3 perpendicular to the base;fixed gripping means or clamps 4 and 5 supported on arm 2; rotatableclamps 6 and 7 supported on arm 3, each being opposite one of the fixedclamps 4 and 5, and being carried for rotation on rotatable spindles 10and 11 respectively; passage 12 axially through rotatable spindle 10 tofacilitate transmittal of twist between the interior gripping locationestablished at 6 and the main length of the cord Y; and coupling wheel13 adapted eg by gearing to cause both rotatable spindles to besimultaneously driven an equal number of turns in the same sense.

The passage 12 should be approximately axially through the rotatablespindle 10 to position the cord fairly close to its axis of rotation. Itis convenient to provide the passage with a longitudinal slot 14 so thatthe cord can be removed laterally from the passage. Alternatively therotatable support mechanism can be in the form of a large collet-likemember through which cord can pass without interference during acontinuous cord handling operation.

Various coupling means can be employed in the apparatus of thisinvention to secure equal and simulta neous rotation of the rotatableclamps. Such suitable coupling means include intermeshed gear teeth orinteracting resilient surfaces on the periphery of each rotatablesupport; non-slipping flexible belt encompassing frictionally contactedwhorls or the like to drive said rotatable supports; magnetic couplings;electrical couplings via selsyn motors; and other means analogousthereto. The power transmitting means which supplies the rotationalforce to the rotatable spindles may comprise; a handle device such asshown in FIGURE 1 for manual operation; knurled outer peripheries of therotatable support for manual operation; axially positioned shafts ordepressed keyways for reception of a shaft for the transmission ofrotational power from a motor or other source; radially extending vanesto transmit pneumatic power; magnetic couplings; and other analogousmeans.

In operation, a first cord X is gripped near one end by rotatable clamp7, and is gripped at an interior location by fixed clamp 4 to make anacute angle between the gripped segment thus formed and the base of thapparatus.

A second cord Y is gripped near one end by fixed clamp 5 and is grippedat an interior location by rotatable clamp 6 making the length of thegripped segment of cord Y approximately equal to that for cord X andaligning the gripped segments close together over a region ofintersection midway between the supporting arms 2 and 3, with their endspointing in opposite directions.

Coupling wheel 13 is then rotated until both gripped segments becomeuntwisted. The individual yarns of each cord are separated and eachseparated yarn of one cord is then paired with a like yarn of the othercord, at staggered sites along the region of intersection of the grippedsegments. The yarn lengths from one interior gripping location to thesite of union of the yarn pair and on to the other interior grippinglocation are equalized for all yarn pairs, and the yarn pairs areunited.

The yarn lengths from the site of union to the end of the yarn are thensevered as close as possible to the site of union. The coupling wheel isnow rotated in the sense opposite to its previous rotation and the samenumber of turns. Thereby the excess twist stored in cord Y interiorly ofthe gripping location at clamp 6 is removed and an equal twist isimparted to the region of splice between clamps 6 and 4.

The spliced cord is then unclamped at 4 and at 6 and is taken out ofpassage 12 through slot 14 in spindle 10.

FIGURE 2 illustrates a preferred apparatus for practicing thisinvention, comprising frame 21 and perpendicular arms 22 and 23 similarto the corresponding members of FIGURE 1. This apparatus also includesfixed clamps 24 and 25 supported on arm 22 one above the other androtatable clamps 26 and 27 supported opposite to the fixed clamps on arm23, generally as in the apparatus of FIGURE 1. In FIGURE 2, threeclamping posts are provided spaced along base 21 namely posts 30, 31 and32 bearing clamps 33, 34 and 35 respectively. The number of posts willbe made equal to the number of yarns or strands composing the cords tobe spliced.

The operation of the apparatus of FIGURE 2 is generally similar to thatof FIGURE 1. In FIGURE 2 an upper cord X is illustrated strung upbetween clamp 24 at the interior of the cord and rotatable clamp 26 nearthe end of the cord. A lower cord Y running in the opposite direction tocord X is illustrated, strung up between fixed clamp 25 near the endthereof and rotatable clamp 27 at the interior thereof. The rotatableclamps 26 and 27 FIGURES 2 are coupled for equal rotation in the samesense, as are the clamps of FIGURE 1. A longitudinal slot 28 in thespindle bearing clamp 27 allows removing the cord from the apparatus.

In operation, as for the apparatus of FIGURE 1, the rotatable spindlesare turned until the twist has been removed from the segment of cord Xbetween clamps 24 and 26 and also from the segment of cord Y betweenclamps 25 and 27.

One of the individual yarns of cord Y is then separated out just beyondpost 30 and a yarn of cord X is also separated near post 30. These twoyarns are clamped together at clamp 33; and the end of each is thensevered at a point beyond the clamp. Adhesive is applied to theresulting free ends, clamp 33 is unfastened and the ends are rolledtogether with the fingers to form a joint. Alternatively, the clamp canbe unfastened first; and as a second alternative the ends can bestitched side by side with a hand zig-zag stitcher. The remaining twoyarns of each of the cords are similarly paired in the vicinity of posts31 and 32 respectively, the pairs clamped at 34 and 35 respectively, andthe yarn pairs united. The rotation of rotatable clamps 26 and 27 isthen reversed as compared to the previous untwisting operation, wherebythe original twist is restored to the segment of the spliced cordbetween clamp 24 and clamp 27. The finished spliced cord is unclampedfrom clamp 24 and is removed, through slot 28, from the apparatus.

It will be appreciated that clamps 33, 34 and 35 should be set atheights such that the yarn paths from clamp 24 to clamp 27 via each ofthe clamps 33, 34 and 35 will all be equal. With the string up shown inFIGURE 2 where yarn cord X is an upper cord and cord Y is a lower cord,a suitable arrangement will be make clamp 33 the highest clamp above theline of the upper cord, clamp 34 the lowest clamp about at the line ofthe lower cord, and clamp 35 at an intermediate height about at the lineof the upper cord as illustrated in FIGURE 2. Alternatively, the cordscould be strung up to intersect as in FIGURE 1 and each of the clamps33, 34 and 35 could be at an intersection of a yarn of one cord with ayarn of the other cord. The arrangement shown in FIGURE 2 isparticularly convenient to allow easy handling of the individual yarnsand arrangement thereof in pairs which can conveniently be joined.

The spliced cord produced using the apparatus of FIGURE 2 can readily bemade free of protruding ends whereby the splice will have a minimumadverse effect on the handling characteristics of the cord. The splicewill have excellent strength, at least 75% of the tensile breakingstrength of the unspliced cord; will have the same twist in the regionof splice as in the unspliced lengths; will have denier no more thanabout (100/ n) greater than that of the unspliced lCOI'd lengths, nbeing the number of yarns or plies composing the cord. The flexibilityof the cord in the region of splice will be essentially the same as thatin the unspliced lengths.

The tfolowing examples describe specific embodiments of the inventionbut are not intended to be considered as limitati-ve of the scope of theinvention.

EXAMPLE 1 The apparatus of FIGURE 2 was employed in the splicing of athree ply cord consisting of 6,720 denier 1088 filament 5.0 Z twistpolycaproamide yarns, said cord having 5.0 turns per inch S twist. Thesegments of cord between the fixed \clamps and the rotating clamps were20 inches long, and mounted three inches apart, one above the other. Theclamping posts along the base (30, 31, and 32 of FIGURE 2) were atS-inch intervals. Spring clamps inch wide were mounted thereon. The

heights of the several clamps above the base were as follows:

Clamp No Inches 24 5 25 3 A 26 6 /2 27 4% 33 6 /2 34 3% 35 5 /2 Theoperation was as :above described in connection with FIGURE 2. Thesegments were simultaneously untwisted by the simultaneous rotation ofthe rotatable clamps. The three yarns composing each cord were separatedand paired with those of the other cord, and each pair was clamped atone of the clamps 33, 34, 35. The yarn ends were cut 0E to within about/2 inch of the site of clamping. An adhesive composition of 12%polycaproamide (20,000 molecular weight, by viscosity measurement)dissolved in 2,2,3,3-tetrafiuoropropanol was then applied manually toeach of the six severed ends and, with a slight manual rolling of thesevered end with the adjacent yarn, uniting was effected.

The paired, united yarns were then unclamped and, by rotating therotatable clamp 27 in the reverse sense from its original rotation, anamount of twist was returned to the region of splice equal to the amountoriginally removed from the gripped segment of cord Y and stored in themain length of cord Y. The cord was then unfastened from the stationaryclamp and from the rotatable clamp on the opposite end of the apparatusthrough the longitudinal slot 28.

The splice thereby obtained was found to have 86% of the breakingstrength of the cord, and had a measured increase of denier of 27%.

EXAMPLE 2 The apparatus of FIGURE 1 was employed in the splicing of atwo ply cord consisting of 6,720 denier 1088 filament 5 .0 Z twistpolyethylene terephthalate yarns, said cord structure having 5.0 turnsper inch S twist. Two twenty inch cord segments were mounted between thefixed and the rotatable clamps, parallel and three inches apart, withtheir ends at opposite ends of the apparatus.

The operation was essentially as described in connection with FIGURE 1.The cords were simultaneously untwisted by simultaneously rotating, inthe same sense and the same number of turns, the coupled spindles 10 and11. The individual yarns were paired and were sewn over a 1% inchoverlapping length employing a 'Pfaff Model 259 portable zig-zagstitcher manufactured by the Pfaff International Corp., NY. A distanceof three inches separated the two sites of union. The stored twist wasthen returned to the region of the splice by rotation of the spindlesback to their starting point. The splice thereby obtained was found tohave 77% of the breaking strength of the unspliced cord and had ameasured increase in denier of about 37% over the region of the spliceextending from the beginning of one site of union to the end of thesecond site of union.

I claim:

1. A spliced multi-ply twisted structure having throughout, includingthe region of splice, the same twist; having in the region of spliceseveral sites of union wherein the union is comprised of paired yarnsoverlapped A1 to 3 inches to join said paired yarns together to impartimproved uniformity and flexibility to the region of splice, said sitesof union being staggered with respect to each other uniformly along thelength of said splice to produce no greater denier than about d (1+1/n)when d is the denier of the main length of the spliced structure and nis the number of individual yarns composing the structure; and having atensile strength of the splice 7 at least 75 percent of the tensilestrength of the unspliced yarn.

2. The spliced multi-ply twisted structure of claim 1 wherein the saidpaired yarns provide a uniform union site whereby said spliced structureis free of protruding yarn ends.

References Cited UNITED STATES PATENTS 411,637 9/1889 Batchelor et a1.57142 XR 8 Verrill 57142 XR Macintosh 5722 Pearson et a1 5722 Kelly 5722Pearson et a1. 5722 Greene 57142 XR Gathman 57142 JOHN PETRAKES, PrimaryExaminer.

